Sustaining living rivers

Rivers cannot continue to meet society's needs, or the needs of living things, if humans continue to regard river management as a purely political or engineering challenge. The flow of rivers is part of a greater flow, the planet's water cycle, which sustains not only the flow of water but the entire web of life. Ultimately, the condition, or health, of the aquatic biota is the best means of understanding and controlling humans' impact on the Earth's watercourses and on the whole water cycle. Biological monitoring, especially multimetric approaches such as the index of biological integrity, acknowledges the importance of rivers' biotic integrity and offers one of the strongest available tools for diagnosing, minimizing, and preventing river degradation. The broad perspective offered by biological evaluations stands a better chance than narrow chemical criteria or conventional measures of urban development of sustaining living rivers.